Toothbrush comprising asymmetrically oriented tufts of bristles

ABSTRACT

A toothbrush includes a handle and a bristle-carrying head part, which are connected to each other by a neck part, the head part having a multiplicity of tufts of bristles consisting of bristles. An anchor is oriented at right angles to the longitudinal axis. Two or more tufts of bristles have a bristle tuft half with bristle ends standing up higher in relation to the bristle ends of the other bristle tuft half.

This application is a divisional application of U.S. application Ser.No. 15/403,878 filed Jan. 11, 2017, which in turn is a divisionalapplication of U.S. application Ser. No. 13/817,310 filed Feb. 15, 2013,now U.S. Pat. No. 9,572,417, which in turn is a U.S. national stageapplication of PCT/EP2011/001144 filed Mar. 9, 2011. Each of the priorapplications is incorporated herein by reference in its entirety.

BACKGROUND

The present invention concerns a toothbrush and a process for producinga toothbrush.

Toothbrushes usually have a brush head with a bristle area formed bytufts of bristles. Such toothbrushes have long been known. Over thecourse of time, the bristle areas of such toothbrushes have undergonevaried designs and further developments to improve on the one hand thecleaning effect and on the other hand the comfort or convenience for theuser. One of these developments concerns the use of profiled bristleareas and tufts of bristles with bristles standing up to differentheights in the tuft of bristles.

The document U.S. Pat. No. 5,926,897 discloses a toothbrush with abristle area consisting of tufts of bristles. This bristle area is of aprofiled configuration and the individual tufts of bristles have anumber of bristles standing up higher, which form a higher end area.

The document DE 198 32 436 describes a process for producing brushes, inparticular toothbrushes. The process shows the working of tufts ofbristles with bristles of different lengths, the working of the bristlesbeing carried out in various steps by means of lateral deflection.

US Design 425,306 shows an ornamental bristle area with substantiallytriangular tufts of bristles, at the corners of which higher bristlesare arranged.

The document EP 1 425 989 discloses toothbrushes with pointed bristlesand a process for producing the same. The bristles may in this case havetwo identical pointed ends or different ends, that is to say anon-pointed end and a pointed end.

The document WO 2009/000903 describes a toothbrush with tufts ofbristles which have on the one hand shorter, non-pointed bristles and onthe other hand longer, pointed bristles. The longer bristles may berandomly distributed in the tuft of bristles or arranged centrally in aninner region of the tuft of bristles.

Various efforts aimed at providing toothbrushes which comprise a bristlearea that has bristles with bristle ends standing up to differentheights in a tuft of bristles are known from the prior art. However, thecorresponding processes are complex or only allow a restricted design ofthe bristle area.

SUMMARY

The present invention is therefore based on the object of providing atoothbrush which comprises an improved cleaning effect, in particular ofthe interdental spaces, while the toothbrush is produced as simply aspossible in a process that is as reliable as possible.

The object is achieved by a toothbrush as described herein and a processwith the features described herein.

A toothbrush according to the invention has a handle and abristle-carrying head part. The handle and the head part are connectedto each other by means of a neck part. The head part carries thebristles and consequently has tufts of bristles, which for their partcomprise a multiplicity of bristles or bristle filaments. Theexpressions bristle, filament and bristle filament are used synonymouslyhereafter and refer to an individual bristle filament. These bristlefilaments are produced by means of an extrusion process and are cut tothe correct length before they are fixed on the toothbrush. For thisreason, in their unworked state, the bristle filaments have acylindrical cross section. This cross section is usually circular, butmay also have a form deviating from a circle.

With preference, the bristles or the tufts of bristles extend in aperpendicular direction away from the head part. In an alternativeembodiment, the tufts of bristles according to the invention may alsoextend from the head at an angle. At least two of the tufts of bristlesof the head part comprise at least one bristle which has a bristle endthat stands up higher in relation to the bristle ends of the otherbristles of the tuft of bristles. The at least one bristle with thehigher bristle end is arranged non-centrally within the tuft ofbristles. If a number of bristles with a higher bristle end are present,they are also arranged non-centrally within the tuft of bristlescomprising them.

Furthermore, the at least two tufts of bristles which comprise at leastone bristle with a higher bristle end are preferably arranged onopposite sides of an (imaginary) central longitudinal plane of thetoothbrush.

The (imaginary) central longitudinal plane is at right angles to thebristle area in the head of the toothbrush. Moreover, the centrallongitudinal plane runs through the longitudinal axis of the toothbrush.All the tufts of bristles of the head part preferably run at leastapproximately parallel to the central longitudinal plane.

The two or more tufts of bristles that have at least one bristle with ahigher bristle end are arranged on the opposite sides of the centrallongitudinal plane in such a way that one half, which comprises at leastone bristle with an end standing up higher, is oriented toward thecentral longitudinal plane. Alternatively, the converse arrangement isalso possible, so that the ends standing up higher are oriented awayfrom the central longitudinal plane.

In an alternative embodiment, the toothbrush according to the inventionhas the following features: a toothbrush with a handle and abristle-carrying head part, which are connected to each other by a neckpart, the head part having a multiplicity of tufts of bristlesconsisting of bristles, two or more tufts of bristles having at leastone bristle with a bristle end standing up higher in relation to thebristle ends of the other bristles, the at least one bristle with ahigher bristle end being arranged non-centrally within the tuft ofbristles, and the two or more tufts of bristles being arranged onopposite sides of a central longitudinal plane of the toothbrush and allthe tufts of bristles being oriented uniformly with one half of the tuftof bristles that comprises the at least one bristle with a higherbristle end being oriented toward or alternatively away from the centrallongitudinal plane.

In a preferred embodiment, the tufts of bristles are fastened on thehead part by means of an anchor. Bristling processes which fasten tuftsof bristles by means of an anchor in corresponding blind holes of thehead part are known per se. By means of the anchor, the tufts ofbristles are symmetrically or asymmetrically folded and subsequentlyfixed in blind holes. The folding by means of the anchor has the effectthat the tuft of bristles has two halves (bristle tuft halves), whicheach comprise one of the ends of the folded bristles.

In a further preferred embodiment, the bristles with a higher bristleend are arranged in the half of the tuft of bristles comprising themsubstantially in one region of this half. This means that the bristleswith a higher bristle end are not randomly distributed within the halfof the tuft of bristles comprising them but are substantiallyconcentrated on one region of this half. In this region, there may alsobe bristles which do not have a higher bristle end.

In a preferred embodiment, all the anchors have the same orientation.They are, for example, aligned parallel to the central longitudinalplane.

In another embodiment, the anchors have at least two orientations. Someof the anchors may, in turn, be oriented parallel to the centrallongitudinal plane, while others of the anchors are not aligned parallelto the central longitudinal plane but form or include an angle with thisplane. This angle is preferably in the range from 0° to 90°, withparticular preference in the range from 0° to 30°.

In a preferred embodiment, the two or more tufts of bristles which haveat least one bristle with a higher end are arranged mirror-invertedly inrelation to the central longitudinal plane.

In a further embodiment, the anchors are oriented substantiallyperpendicular to the longitudinal axis of the toothbrush. This meansthat the anchors include an angle with the longitudinal axis of90°+/−20°, preferably 90°+/−10°. This angle may vary over the tufts ofbristles of a toothbrush. In this embodiment it is possible to orientthe higher bristle ends in the tufts of bristles the same in each case.Consequently, the higher bristle ends of at least one tuft respectivelystand substantially either on the handle side or on the free side of thetoothbrush.

Furthermore, the tufts of bristles may be oriented alternately row byrow, i.e. the first row of tufts of bristles on the side of the free endof the toothbrush has the lower bristle ends on the side of the free endof the toothbrush. The next row has the higher bristle ends on the sideof the free end of the toothbrush. This achieves the effect that theinterdental penetration is improved. The distances between the clusterswith the higher bristle ends becomes greater, so that the engagement ofthese becomes better. These tufts of bristles are preferably not thinnedout.

Consequently, a symmetrical pattern of the tufts of bristles withrespect to the longitudinal center axis of the toothbrush is preferablyproduced.

It is also possible to combine the stated tuft orientations in onebristle area.

In a further embodiment, bristles that are pointed at one end are used.These are produced from cylindrical bristles, by rounding them at thefree end, preferably on the bristle strand, in a first step andsubsequently cutting them to the correct length. Alternatively,cut-to-size bristles are rounded at one end of the bristles only afterthey have been cut from the bristle strand.

Subsequently, they are pointed at the end opposite from the rounded end,and possibly colored. After that, they can be inserted into atoothbrush. In this case, the pointed ends form the higher bristle endsand the rounded ends form the lower bristle ends. The bristles, or tuftsof bristles, produced in this way are preferably neither rounded off northinned out after anchoring in the brush head.

In the case of a particularly preferred toothbrush with a handle and abristle-carrying head part, which are connected to each other by a neckpart, the head part has a multiplicity of tufts of bristles, consistingof bristles, respectively forming two bristle tuft halves and fastenedin the head part by means of an anchor. The anchor of at least one tuftof bristles is oriented at least approximately at right angles to alongitudinal axis of the toothbrush and at least two tufts of bristleshave a bristle tuft half with bristle ends standing up higher inrelation to the bristle ends of the other bristle tuft half. Withparticular preference, one of these at least two tufts of bristles isthe one which is fastened with the anchor oriented at leastapproximately at right angles to the longitudinal axis of thetoothbrush. Further preferred embodiments of this toothbrush arespecified in the following paragraphs.

With preference, the bristles are bristles that are pointed at one end.

With preference, the pointed ends of the pointed bristles form thehigher bristle ends.

With preference, the anchor of a number of tufts of bristles is orientedat least approximately at right angles to the longitudinal axis of thetoothbrush and the relevant bristle tuft halves with the higher bristleends are facing the neck part and the relevant bristle tuft halves withthe lower bristle ends are facing away from the neck part. Withparticular preference, this applies to all the tufts of bristles.

It is also preferred for the anchor of a number of tufts of bristles tobe oriented at least approximately at right angles to the longitudinalaxis of the toothbrush and the relevant bristle tuft halves with thehigher bristle ends of tufts of bristles neighboring in the direction ofthe longitudinal axis of the toothbrush to be facing one another. Withparticular preference, this applies to all the tufts of bristles.

It is also preferred for the anchor of a number of tufts of bristles tobe oriented at least approximately at right angles to the longitudinalaxis of the toothbrush and for the relevant tufts of bristles to bearranged in rows running transversely to the longitudinal axis of thetoothbrush and arranged one behind the other in the direction of thelongitudinal axis of the toothbrush. The tufts of bristles are in thiscase oriented identically in rows and the relevant bristle tuft halveswith the higher bristle ends of the tufts of bristles of one row and therelevant bristle tuft halves with the higher bristle ends of aneighboring row are facing one another or facing away from one another.With particular preference, the anchors of all the tufts of bristles areoriented at least approximately at right angles to the longitudinal axisof the toothbrush and the above applies to all the tufts of bristles.Furthermore, with preference, the rows run at right angles to thelongitudinal axis of the toothbrush.

In the case of a further preferred embodiment, the anchor of a number oftufts of bristles is oriented at least approximately at right angles tothe longitudinal axis of the toothbrush and the relevant bristle tufthalves with the higher bristle ends are facing away from the neck partand the relevant bristle tuft halves with the lower bristle ends arefacing the neck part. With preference, this applies to all the anchorsand all the tufts of bristles.

In the case of a process for producing an aforementioned particularlypreferred toothbrush with a handle and a bristle-carrying head part,which are connected to each other by a neck part, tufts of bristlesconsisting of a multiplicity of bristles and respectively forming twobristle tuft halves are fastened in blind holes in the head part bymeans of an anchor. The anchor of at least one tuft of bristles ispunched into the head part such that it is oriented at leastapproximately at right angles to the longitudinal axis of thetoothbrush. The bristles of at least two tufts of bristles are foldedasymmetrically about the anchor, whereby one bristle tuft half hasbristle ends standing up higher in relation to the bristle ends of theother bristle tuft half.

In the case of this process, bristles that are pointed at one end areused with preference as bristles.

With preference, the bristles are pointed and/or rounded at the twobristle ends thereof before they are introduced into the blind holes ofthe head part.

With preference, these bristles are no longer worked after they havebeen introduced into the blind holes.

The higher bristle ends are arranged such that they stand up higher inrelation to the bristle ends of the other bristles by 0.5 mm to 5 mm.With preference, they are 2 mm to 3 mm higher than the bristle ends ofthe other bristles.

The tufts of bristles of the head part may comprise bristles withdifferent bristle ends. Apart from cylindrical bristles with rounded-offends, there may also be bristles with a pointed end. Preferably, thecross section is circular, but may also have a form deviating from acircle.

In another embodiment, the head part has in addition to conventional,extruded bristles with rounded-off or pointed bristle ends, at least onesoft-elastic structure. This soft-elastic structure is preferablyconfigured as a cleaning and massaging element. As a difference from thebristles, the soft-elastic structures are preferably produced togetherwith the toothbrush handle by means of an injection-moulding technique,for example in the two- or multi-component injection-molding process.

A device for providing a toothbrush with bristles comprises a tuftingdevice with a bristle feed and a bristle tuft conveyor with a notch. Thebristle tuft conveyor is assigned a stop for the tufts of bristles. Inthis case, the stop and/or the bristle feed are adjustableperpendicularly to a plane of movement of the tuft conveyor.

The stop is in this case preferably adjustable in its height between 2mm and 30 mm, with particular preference between 4 mm and 10 mm.

To ensure movement of the bristles that is as good as possible, the stophas a polished surface, that is to say a polished supporting surface, ina region in which it comes into contact with bristles.

In a preferred embodiment of the device for providing toothbrushes withbristles, the distance between the supporting surface of the stop andthe tuft conveyor is kept constant (parallel planes). This means thatthe supporting surface of the stop and the tuft conveyor are arranged inparallel planes.

In another embodiment, the distance between the supporting surface ofthe stop and the tuft conveyor is variable. In this case, the distance Adecreases in a direction leading away from the material channel, that isto say the planes are at an angle to each other.

In a process for producing a toothbrush, the toothbrushes are providedwith bristles by a device described above.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is explained in more detail below with referenceto the drawing, in which, purely schematically:

FIG. 1 shows the view of a toothbrush head in the direction of thelongitudinal axis of the toothbrush;

FIG. 2 shows a tuft of bristles in the direction of the longitudinalaxis of an anchor;

FIG. 3 shows a tuft of bristles in the transverse direction in relationto the longitudinal axis of the anchor;

FIG. 4 shows a possible arrangement of the anchors in a head part of atoothbrush, with bristles omitted;

FIG. 5 shows an enlarged representation of the end region of the headpart shown in FIG. 4, with bristles represented;

FIG. 6 shows a plan view of an enlarged tuft of bristles from FIG. 5;

FIG. 7 shows a plan view of a bristle tuft conveyor and a bristle feedwith two material channels;

FIG. 8 shows one possible position of an adjustable stop in relation toa bristle tuft conveyor and a material channel;

FIG. 9 shows a further possible position of an adjustable stop inrelation to a bristle tuft conveyor and a material channel from FIG. 8;

FIG. 10 shows one possible position of an adjustable stop in relation toa bristle tuft conveyor and an adjustable material channel;

FIG. 11 shows a further possible position of an adjustable stop inrelation to a bristle tuft conveyor and an adjustable material channelfrom FIG. 10;

FIG. 12 shows a segment of a displacement rail of the device;

FIG. 13 shows a sequence as carried out by the displacement rail shownin FIG. 12;

FIG. 14 shows the form of the end region of a cylindrical rounded-offbristle (FIG. 14a ) and of a cylindrical pointed bristle (FIG. 14b );

FIG. 15 shows a further possible arrangement of the anchor in a bristlearea on a toothbrush, in plan view;

FIG. 16 shows a variant of the provision of bristles, with the anchorpositions shown in FIG. 15, in side view;

FIG. 17 shows a further variant of the provision of bristles, with theanchor positions shown in FIG. 15, in side view;

FIG. 18 shows a further variant of the provision of bristles, with theanchor positions shown in FIG. 15, in side view;

FIG. 19 shows a further possible arrangement of the anchors in a bristlearea of an electrically operated toothbrush with rotating or oscillatingmotion, in plan view;

FIG. 20 shows a further variant of the provision of bristles, with theanchor positions shown in FIG. 19, in side view;

FIG. 21 shows a further variant of the provision of bristles, with theanchor positions shown in FIG. 19, in side view;

FIG. 22 shows a further possible arrangement of the anchors in a bristlearea of an electrically operated toothbrush with rotating or oscillatingmotion, in plan view; and

FIG. 23 shows the process sequence for producing bristles that arepointed and colored at one end, with a rounded cylindrical bristle end.

DETAILED DESCRIPTION

FIG. 1 shows a view of a head part 10 of a toothbrush (also referred toherein as a toothbrush head) in the direction of the longitudinal axis29 of the toothbrush perpendicular to the viewing plane. The tufts ofbristles 20 shown are arranged in a transverse row on the head part 10and extend at least approximately, here exactly, perpendicularly awayfrom the head part 10. The tufts of bristles 20 comprise bristles 21with a bristle end 37 standing up higher in relation to the otherbristles. In the embodiment shown, the bristle tuft half 35 of the tuftsof bristles 20 which comprises the bristles 21 with higher bristle ends37 on the opposite sides of the central longitudinal plane 30 arerespectively oriented toward this central longitudinal plane.Accordingly, the majority of the bristles with lower bristle ends 38 arefacing away from the central longitudinal plane. The six tufts ofbristles 20 shown accordingly have different orientations on theopposite sides of the central longitudinal plane 30, this characteristicbeing easy to see from the higher bristle ends 37.

The bristles 21 are arranged in this way on the entire toothbrush, apartfrom tufts of bristles 20 which are arranged on the longitudinal axis29. The tufts that are arranged on the longitudinal axis 29 may beoriented toward one or the other side of the longitudinal axis or of thecentral longitudinal plane. In the profile of the bristle ends, thehigher position and lower position of certain bristle ends with respectto other bristles produce two levels of ends, the higher bristle ends 37penetrating into the interdental spaces better than the lower bristleends 38.

In the representation of FIG. 1, and also the subsequent FIG. 2, thespacing brought about by the anchor 45 holding them in the brush head 10in the known manner is in each case shown as being relatively clear. Thedrawings are schematic; in reality, the bristles “splay” somewhat andthe spacing is no longer visible at the end of the tuft of bristles 20,or even already at the level of the lower bristle ends 38.

A conventional and known process for providing toothbrushes withbristles is that of fastening the tufts of bristles 20 in the head part10 by means of anchors 45. In FIG. 2, a detailed view of a tuft ofbristles 20 is shown in the direction of the longitudinal axis of ananchor 45. The anchor 45 folds the tuft of bristles 20 into two parts.During the tufting of the tufts of bristles 20 in blind holes 40 of thehead part that are provided for this purpose, the anchor 45 firmlyclamps the bristles 21 in the blind hole. The anchor 45 therebypenetrates into the plastic that surrounds the respective blind hole 40and in this way anchors itself at the respective position. The bristles21 are consequently firmly clamped between the wall of the blind hole 40and certain surfaces of the anchor 45.

In the case of conventional toothbrushes, the folding of the bristles 21by the anchor 45 takes place symmetrically, that is to say that there isthe same length of bristle on both sides of the anchor 45. In the caseof the present invention, however, the tufts of bristles 20 are foldedasymmetrically. The three tufts of bristles 20 shown, with the higherand lower bristle ends 37, 38, are all oriented identically in thepresent example, i.e. the higher bristle ends 37 are always obtained onthe same side of the anchor 45. It is generally the case that the higherbristle ends 37 are always arranged on the same side of the anchor 45.It is not the case that some of the higher bristle ends are arranged onthe left side of the anchor and others are arranged on the right side ofthe anchor.

FIG. 3 shows tufts of bristles 20 in the transverse direction inrelation to the longitudinal axis of the anchor 45. In this case, thesection through the blind hole 40 is shown only in the case of one tuftof bristles 20. From this view, in combination with FIG. 2, it becomesclear that only a relatively small number of the bristles 21 of a tuftof bristles 20 have bristle ends 37 which stand up higher in relation tothe bristle ends 38 of the other bristles 20. In FIG. 3, it can also beseen well how much the anchor 45 penetrates into the plastic surroundingthe blind hole 40. The edge of this trace of the penetration isrepresented in the figure by dashed lines.

The length ratios in the tufts of bristles 20 of the finished toothbrushare such that, from leaving the blind hole 40 to the higher bristle ends37, the tuft of bristles 20 has in each case a length of 9 mm to 15 mm,preferably from 10 mm to 12 mm. The length from leaving the blind hole40 to the lower bristle ends 38 is between 6 mm and 11 mm, preferably 8mm to 10 mm. The higher bristle ends 37 are arranged such that theystand up higher in relation to the bristle ends 38 of the other bristlesby 0.5 mm to 5 mm. With preference, they stand up higher than thebristle ends 38 of the other bristles by 2 mm to 3 mm.

In FIG. 4, a possible arrangement of the anchors 45 by means of whichthe tufts of bristles 20 are fastened in the head part 10 of thetoothbrush is shown. The neck part 15 adjacent the head part 10 is onlypartially depicted; a handle adjoins the neck part 15 in a known manner.

In the embodiment shown, all the anchors 45 have the same orientation oralignment with respect to the longitudinal center axis 29. In thepresent example, the angle which is included by the anchor 45 and thelongitudinal center axis 29 is 0°. The angle may preferably lie in arange between 0° and 30°.

To embody the invention, the tufts of bristles 20 are arranged on thehead part 10 in transverse rows. In FIG. 4, the bristles 21 are notshown for representational reasons.

FIG. 5 shows an enlarged representation of the free end region of thehead part 10 shown in FIG. 4, this time with bristles 21 shown. Thetufts of bristles 20 arranged in transverse rows can in turn be seen.

The anchor 45 of the tuft of bristles 20 divides this tuft of bristlesinto two halves in plan view. The bristle tuft half 35 of the tuft ofbristles 20 that comprises the bristles 21 with higher bristle ends 37is in this case oriented toward the central longitudinal plane 30. Thehigher bristles 37 are represented in the figure as shaded. The bristletuft half 36 of the tuft of bristles 20 that is facing away from thecentral longitudinal plane 30 only comprises bristles 21 with lowerbristle ends 38.

It can likewise be seen in this view that the bristle tuft halves 35 ofthe tufts of bristles 20 with bristles which have a bristle end 37standing up higher in relation to the other bristles also comprisebristles with a lower bristle end 38.

In the case of the tufts of bristles 20 arranged on the head part 10 intransverse rows, the anchors 45 aligned parallel to the centrallongitudinal plane 30 produce a mirror-inverted arrangement of the tuftsof bristles 20. Excluded from this are tufts of bristles through whichthe central longitudinal plane 30 passes. In such tufts of bristles 20,the bristles 21 with higher bristle ends 37 face either one or the otherside of the central longitudinal plane 30.

The arrangement of the higher and lower bristle ends 37, 38 is alsopossible in a conversely oriented manner, so that the higher bristleends 37 are directed away from the central longitudinal plane 30 and thelower bristle ends 38 are directed toward the central longitudinal plane30. An important point in this respect is that the anchor 45, whichfixes the tufts of bristles in the head part 10, may also assume anangle in relation to the longitudinal axis 29. In this case, one speaksof higher bristle ends 37 oriented toward the central longitudinal planeif they are arranged in the angle, i.e. the area, between 0° and 89.99°between the longitudinal axis of the anchor and the central longitudinalplane 30. Conversely, one speaks of higher bristle ends 37 oriented awayfrom the central longitudinal plane 30 if the lower bristle ends 38 arearranged in the way just described.

FIG. 6 shows a plan view of a single tuft of bristles 20 from FIG. 5,shown enlarged. The anchor 45 divides the tuft of bristles 20 into twobristle tuft halves 35 and 36. In this case, the bristle tuft half 36only comprises bristles 21 with lower bristle ends 38, that is to saythat all the bristles 21 in the bristle tuft half 36 stand up (at leastapproximately) to the same height. By contrast with this, in the bristletuft half 35 there are both bristles 21 with higher bristle ends 37 andbristles 21 with lower bristle ends 38. In the example, the bristles 21with higher bristle ends 37 are arranged in a contiguous region 39 ofthe bristle tuft half 35.

In FIG. 7, a plan view is shown of a bristle tuft conveyor 50 and abristle feed 55 with two material channels 60 of a tufting machine fortoothbrushes (a bristle-providing machine). The bristles 21 are pushedtoward the bristle tuft conveyor 50 in the two material channels 60 bypushers 62. The bristle tuft conveyor 50 is mounted rotatably about anaxis about which it performs a forward-backward rotating movement. Theextent of the rotation is defined by various points that the notch 51must run to. On the one hand, this is the reversal point at the end ofthe material channels 60, on the other hand the point at which the tuftis punched into the blind hole 40 with the anchor 45. When the notch 51travels along the material channels 60 during the rotation and at thismoment is not filled, it fills itself with bristles 21. The removal ofbristles 21 at the end of the material channels 60, that is to say atthe end opposite from the pusher 62, has the effect that the bristles 21in the material channel 60 are transported in the direction of thebristle tuft conveyor 50.

The bristles 21 from the different material channels 60 may havedifferent properties, for example different colors. To take the bristles21 from one or the other material channel 60, the corresponding materialchannel 60 must move laterally during the phase of the process in whichthe rearward end of the bristle tuft conveyor 50 closes the materialchannel 60, in order that the correct material channel 60 is availablefor filling the notch 51.

FIG. 8 shows one possible position of an adjustable stop 65 in relationto a bristle tuft conveyor 50 and a material channel 60. This could bethe case, for example, in the upper material channel 60 from FIG. 7.

In FIG. 8, the pusher 62 conveys the bristles 21 in the conveyingdirection L to the bristle tuft conveyor 50. The stop 65 is arrangedsuch that it can be adjusted by a drive means 66 in its height, i.e. ina direction M perpendicular to the plane of movement of the bristle tuftconveyor 50, or the axis of rotation thereof, or parallel to thebristles 21 in the material channel 60. When bristles 21 are beingtransported from the material channel 60 to the bristle tuft conveyor50, in the present case the adjustable stop 65 is positioned at theheight of the material channel base 61. As a result, the bristles 21 areguided or supported continuously at at least one of their ends from thematerial channel 60 until they are removed from the notch 51, in orderthat they do not fall out of the notch 51 or become stuck in the notch51. The distance A between the bristle tuft conveyor 50 and the stop 65is constant. In the position of the stop 65 that is shown, the bristletuft conveyor 50 is in a first position in relation to the bristles 21or the length thereof.

In FIG. 9, the lower material channel 60 from the example from FIG. 7 isrepresented. The two material channels 60 that are shown in FIGS. 8 and9, or the corresponding material channel bases 61, are arranged atdifferent levels with respect to the bristle tuft conveyor 50. Each ofthe arrangements represents an orientation of the higher bristle ends 37in the finished toothbrush. At the same time, however, the bristle tuftconveyor 50 is always arranged at the same position, it is fixed interms of its position.

FIG. 9 shows a further possible position of an adjustable stop 65 inrelation to a bristle tuft conveyor 50 and a material channel 60. Thebristles 21 are in a different position in relation to the bristle tuftconveyor 50 than those shown in FIG. 8. In the position shown of thestop 65, the distance between the stop 65 and the bristle tuft conveyor50 has been reduced, so that the bristle tuft conveyor 50 or the notch51 is now no longer located at the same point in relation to thebristles 21 as that shown in FIG. 8. The bristles 21 are in turntransported in the conveying direction L toward the bristle tuftconveyor 50.

The bristles 21 introduced into the toothbrush head 10 by the devicesfrom FIGS. 8 and 9 have a quite specific orientation with respect to thecentral longitudinal plane 30. All the bristles 21 introduced by thedevice shown in FIG. 8 have a specific orientation with respect to thecentral longitudinal axis 30 of the toothbrush. The bristles 21introduced by the device shown in FIG. 9 have the opposite orientation.Thus, for example, the bristles 21 of the toothbrush shown in FIG. 1 aredispensed from two such devices. The bristles 21 on the left side of thecentral longitudinal plane 30 may, for example, be dispensed by thedevice shown in FIG. 8, those on the right side by the device in FIG. 9.Accordingly, all the tufts of bristles 20 that are dispensed by onedevice are oriented in the same direction. The arrangements of materialchannel 60, stop 65 and bristle tuft conveyor 50 in FIGS. 8 and 9 thatare respectively described as a single device in this paragraph togetherform a single device such as that represented for example in FIG. 7. Onefigure (FIG. 8 or 9) shows the upper material channel 60, the other thelower material channel 60. Which material channel has whichconfiguration is of no relevance for embodying the process according tothe invention.

Of central importance for the present invention is the so-calledasymmetric punching. This means that the anchor 45 is not introducedcentrally with respect to the length of the bristles 21, as is normallythe case with tufts of bristles with bristle ends all of the sameheight.

With respect to the bristle tuft conveyor 50, as it is shown for examplein FIGS. 8 and 9, the anchor 45 is introduced directly above it. Since,in the two figures, the bristle tuft conveyor 50 assumes two differentpositions with respect to the length of the bristles, two differentasymmetries are produced. In one case, the ends on one side of theanchor are higher, in the other case the other ends are higher. In FIG.8, for example, the anchor 45 is introduced closer to the upper end ofthe bristles 21, that is to say that the bristle ends which touch thematerial channel base 61 stand up higher. In FIG. 9, the situation isprecisely reversed, the bristle ends which touch the material channelbase 61 form the lower bristle ends when they have been introduced intothe toothbrush head 10.

The adjustable stop 65 is adjustable in direction M between 2 mm and 30mm, preferably between 4 mm and 10 mm. The surface of the stop 65 isalso an important component in the process. To ensure the optimumconveyance of the bristles 21, the surface of the stop 65 is preferablypolished or highly polished. If need be, it is also possible to apply tothe surface a coating which improves the surface. The aim of the surfacetreatment or working is to minimize the frictional resistance betweenthe bristles 21 and the stop 65 and in this way achieve good conveyancein a process that is reliable.

The adjustable stop 65 according to the invention from FIGS. 8 and 9makes it possible in the first place to produce a toothbrush withasymmetrically punched tufts of bristles 20 in a number of orientationsor with different distances between the higher and lower bristle ends37, 38, as explained for example in conjunction with FIG. 1, on abristle-providing machine with a punching unit (bristle-providing unit).This means that, on account of the adjustable stop according to theinvention, advantageously only one anchor-introducing device isnecessary.

A further embodiment of the device according to the invention is shownin FIGS. 10 and 11. The fact that both the material channels 60 and thestop 65 can be adjusted in their position in terms of height means thatfurther possibilities of designing the bristle area are obtained. Asalready in the embodiment shown in FIGS. 8 and 9, the constant in thisarrangement is the bristle tuft conveyor 50, which is arranged fixedlyin terms of its position. The plan view of the device constructed inthis way is the same as in FIG. 7.

FIG. 10 shows one possible position of an adjustable stop 65 in relationto a bristle tuft conveyor 50 and an adjustable material channel 60. Asa difference from the devices shown in FIGS. 8 and 9, in this case boththe stop 65 and the material channel 60 can be adjusted in their height,by a drive means 66, the material channel likewise being assigned adrive means 66. The direction M in which the height of the stop 65and/or the material channel 60 is adjustable is at right angles to theplane of movement of the bristle tuft conveyor 50. Pushers 62 transportthe bristles 21 in the conveying direction L.

In FIG. 11, a further possible position of an adjustable stop 65 inrelation to a bristle tuft conveyor 50 and an adjustable materialchannel 60 from FIG. 10 is shown. In this case, in turn, both thematerial channel 60 and the stop 65 are arranged such that they can beadjusted independently of one another by drive means 66 in their heightperpendicularly in relation to the plane of movement of the bristle tuftconveyor 50. The stop 65, as well as the material channels 60, areadjustable here in height in the direction M between 2 mm and 30 mm,preferably between 4 mm and 10 mm.

The bristles 21 transported in the conveying direction L by pushers 62are supported on the one hand by the material channel base 61 and on theother hand by the stop 65, and so are secured against slipping in theperpendicular direction with respect to the conveying direction L. Whatis special about this arrangement is that the pusher 62 is not adaptedin height. It is always kept in the same plane in relation to thematerial channel base 61, independently of the position of the bristletuft conveyor 50. Therefore, depending on the how the bristle tuftconveyor 50 is set up in relation to the length of the bristles, i.e.depending on the position of the conveyor, it is necessary to provideadditional supporting means at the end of the material channel 60 orabove the ends of the bristles, which however do not restrict thefunctioning of the process. Otherwise, it may be possible for thebristles 21 to be pushed out from the material channel 60perpendicularly on account of the pressure from the pusher 62.

Furthermore, in the situations shown according to FIGS. 10 and 11, itmay be necessary under some circumstances to add a further element whichlies above the material channel 60 and prevents the bristles 21 fromslipping perpendicularly out of the channel during the movement of thematerial channel 60 by drive means 66. Whether such an adaptation has totake place depends on the properties of the bristles 21 (surfacefriction, etc.).

The adjustability of the material channel 60 and of the stop 65 may bevariously designed. For example, the two material channels 60 may beadjusted in height by a single drive means 66. Furthermore, however, itis also possible for the material channels 60 to be configured withindividual drive means 66 and thus made adjustable independently of eachother, which however would necessitate adaptation in the structuraldesign of the arrangement of the material channels. From the aspect ofcosts, however, the second variant does not bring any major advantages,since the variability of the function does not increase. However, thestop must always be adjustable individually, that is to sayindependently of the material channels 60, since this is essentialaccording to the invention.

The possibilities of individualization that are produced by the variouspossibilities for adjustment on the device according to the inventionallow brushes with very special bristle patterns to be created. Forexample, in this way tufts of bristles with different lengths betweenthe higher and lower bristle ends 37, 38 can be achieved on atoothbrush. The drive means 66 may be variously configured.Possibilities for the drive means 66 are, for example, motors (steppingmotors, etc.), pneumatic or hydraulic cylinders, or the like. The stop65 is usually only adjusted when the bristle tuft conveyor 50 is empty,that is to say when no tuft of bristles 20 is being advanced in thenotch 51.

It is important that the various means that are used and come intocontact with bristles 21, from the material channel 60 until thebristles 21 are introduced into the blind holes, are configured veryaccurately and the surface thereof has been optimized, for example bybeing highly polished. As far as the stop is concerned, this has alreadybeen described earlier in the text. Consequently, it is additionallyachieved that the tufts of bristles 20, or the bristles 21 in the tuftsof bristles 20, are introduced into the blind holes 40 in a veryaccurately aligned manner. This is important since the lower bristleends 38 are not cut. Therefore, these bristle ends must already have thenecessary alignment in relation to one another when they are introducedinto the blind hole. Less frictional resistance means in this case fewerdisplacements of the individual bristles 21.

A further configurational possibility for the process is, for example,to provide the stop 65 shown in FIGS. 8 to 11 with a special form. Thestop 65, which in the cases described is of a planar configuration(continuation of the material channel base 61 in a straight lineparallel to the bristle tuft conveyor 50), could be designed here as anangled plane (i.e. it has two partial planes arranged at an angle toeach other). The plane would in this case be designed such that, afterthe continuous transition from the material channel base 61, it has anupward or downward slope along the direction of movement of the tuft ofbristles in the notch 51. The described distance A would therefore nolonger be constant. This could achieve the effect that the asymmetricpunching could, for example, be performed more extremely. However, itwould be necessary to take special measures in order for this to bepossible for both directions of orientation of the tufts of bristles 20in the toothbrush head 10—since the bristle ends which lie against thestop 65 during the conveyance are in one case the higher bristle ends 37and in the other case the lower bristle ends 38 in the finishedtoothbrush. Possible measures here would be, for example, that, inaddition to the movement in height along the direction of movement M,the stop 65 also moves in another direction, and in this way a differentprofile is obtained in the movement curve of the tuft of bristles in thenotch 51 on the stop.

Furthermore, it is also possible for the driven stop 65 to be adjustedduring the conveying of a tuft of bristles. In this case, the adjustmentof the height with respect to the bristle tuft conveyor 50 would bepossible in both directions and the different arrangements of the higherand lower bristle ends 37, 38 could thereby be served.

To create toothbrushes with tufts of bristles 20 of different sizes, abristle tuft conveyor 50 in which a variable notch 51 is made could beused in the process. A variable notch 51 could be adapted in its sizeduring the process, when it is not filled, so that ultimately a greateror lesser number of bristles 21 are transported out of the materialchannel 60 into the blind holes 40.

The configuration of the toothbrush and the orientation of the higherand lower bristle ends 37, 38 are significant for the efficiency of theprocess and also for the cycle time of providing the toothbrush withbristles. The orientation of the tufts of bristles is preferably fixedsuch that, in the bristle-providing process, a number of tufts of thesame orientation can always be introduced into the head part 10. As aresult, the stop 65 and the material channels 60 do not have to bechanged over after every tuft of bristles. The process becomes quickerand also less susceptible to faults.

In the process of providing the toothbrushes with bristles, after theyhave been fastened in the head part 10, the bristles 21 are reworked.This means that they are, inter alia, profiled. The surface profile isachieved, for example, by cutting away or milling away the parts of thebristles that are too long.

Furthermore, they are subsequently rounded.

The further following profiling steps have likewise been furtherdeveloped and supplement the invention. This is explained in detail inconjunction with FIG. 12. So-called displacement rails 70, whichpartially displace the bristles 21 of the toothbrush so as to make thebristles 21 to be worked better accessible, are used in the workingsteps for the profiling of the toothbrushes. According to the invention,in a first step, tufts of bristles 20 are profiled at their higherbristle ends 37. A profiling of the bristle tuft half 36, which consistsonly of lower bristle ends 38, is preferably not performed. Otherwise, acorresponding displacement of the higher bristle ends 37 would benecessary.

FIG. 12 shows a segment of a displacement rail 70 of the device forproviding toothbrushes with bristles. A single tuft of bristles 20 isintroduced into a bristle tuft channel 75 in direction of movement I.The bristle tuft channel 75 runs parallel to the direction of movement Iand the tufts of bristles 20 are advanced in the direction of movement.As this happens, an edge 77 arranged parallel to the longitudinaldirection of the tuft of bristles 20 reaches into the tuft of bristles20 and divides it into two parts. The two parts are not of the samesize. The larger part of the tuft of bristles 20 is then led through adisplacement channel 76. As this happens, the free bristle ends aredisplaced, that is to say deflected and no longer stand up while theyare led through the channel. In terms of the cross section, thedisplacement channel 76 is formed in this region similar to a U profileor V profile, that is to say it is closed on three sides and can in thisway receive the bristles 21.

After the division of the tuft of bristles 20, the less large part ofthe tuft of bristles 20 is likewise displaced by the edge 77 in a firstpart and led into an ordering channel 80, but subsequently releasedagain right away as it runs through. The release takes place in areleasing region 79 as the tuft of bristles 20 is being led through thebristle tuft channel 75. In this releasing region 79, the bristles 21 ofthe tuft of bristles 20 are not displaced, so that the free bristle endsstand up substantially perpendicularly and are shortened to the desiredlength by a cutting knife 78 or some other working means, for example amilling cutter, which moves back and forth at right angles to thedirection of movement I of the tuft of bristles 20 along the directionof movement K of the cutting knife. Subsequently, the bristles 21 notdisplaced are in turn led into a displacement channel 76′, before theyare released again. This displacement of the worked bristles 21 has noprocessing reasons. The displacement is preferably included, however, tostabilize the edge 77. This achieves the effect that the edge 77vibrates less during the working, or is (temporarily) bent less as aresult of the loading, which makes working more difficult, or that thedividing of the tufts no longer takes place constantly, since thereaching of the edge 77 into the tuft of bristles 20 varies.

A complete displacement rail 70 is an arrangement in series of a numberof segments according to FIG. 12, preferably two such segments beingarranged in series with one another. The difference between the twosegments following one after the other may be that the edge 77 ispositioned differently in relation to the tuft of bristles 20, and socan be displaced differently. Moreover, the displacement channel 76 maybe arranged on the other side of the bristle tuft channel 75 in thelongitudinal direction.

For the production of tufts of bristles 21 according to FIGS. 1-3, thedisplacement channel is required in the first part by analogy with thevariant shown in FIG. 12 and in the second part almost in mirror image.This means that the edge 77 is provided such that the smaller part comesto lie on the upper side (see FIG. 12). In addition, the displacementchannel 76 is provided on the other side in the longitudinal directionof the bristle tuft channel 75. The ratios of the division of the tuftsof bristles 20 by the edge 77 are the same in both steps, justdifferently oriented or mirror-inverted.

In FIG. 13, a sequence such as that carried out with the displacementrail shown in FIG. 12 is shown in its individual successive steps. In afirst step, the tufts of bristles 20 arranged in series are separated byintroduction into the bristle tuft channel 75. Subsequently, eachindividual tuft of bristles 20 is divided into two parts, the largerpart of the divided tuft of bristles 20 being displaced, and thereforenot accessible to the cutting knife 78.

For the creation of tufts of bristles 20 according to FIGS. 1-3, thelarger, displaced part of the tuft of bristles 20 comprisesapproximately two thirds of the bristles 21 of the tuft of bristles;generally, the displaced part of the tuft of bristles 20 comprisesbetween 55% and 85%, preferably between 55% and 70%, of the bristles 21.The smaller, not-displaced, part of the tuft of bristles 20 comprises inthe case of FIGS. 1-2 approximately one third of the bristles 21 of thetuft of bristles 20. In a next step, the part of the tuft of bristles 20that is not displaced, and therefore is standing up, is cut to thedesired length. After the cutting operation, the tuft of bristles 20 isreleased again. This means that the displaced part is led out from thedisplacement channel 76. Once the tuft of bristles 20 has been released,the entire operation is repeated, so that each tuft of bristles 20 iscut twice. In this case, different parts of the tuft of bristles 20 arerespectively displaced in the two operations, certain regions beingdisplaced, and accordingly not cut, in both operations.

With regard to the displacement, it is the case that the division of thebristles 21 by the edge 77 is in the range of very small dimensions.Moreover, the form in which the bristles 21 protrude from the blind hole40 is to a certain extent random. It is therefore not possible to defineaccurately how many bristles 21 are, for example, displaced or how manybristles 21 have higher bristle ends 37 in the later, worked case. Thenumbers always vary within certain ranges.

For the actual realization of toothbrushes with transverse rowsaccording to FIG. 1, this means that the toothbrush is oriented suchthat the longitudinal axis 29 of the toothbrush is arrangedperpendicularly in relation to the direction of movement I.

A number of bristle tuft channels 75 are arranged directly next to oneanother, so that a toothbrush comprising a multiplicity of rows, or thetufts of bristles 20 thereof, are worked at least partially in parallel.

If toothbrushes with rows which are arranged at an angle deviating from90° in relation to the longitudinal axis 29 of the toothbrush arecreated, the brush must be introduced into the displacement rail 70 in adifferently oriented manner for the working. In order that theprocessing is possible, the longitudinal axis 29 of the toothbrush isarranged in terms of the angle such that the direction of the rows isparallel to the direction of movement I, i.e. the direction of thebristle tuft channels 75.

It is important in the case of such toothbrushes that all the tufts ofbristles 20 that are to be worked into tufts of bristles 20 with higherand lower bristle ends are arranged in transverse rows which do notoverlap. The symmetries are in this case achieved with respect to anaxis provided at an angle to the longitudinal axis 29.

To illustrate still further the representation of the segment of thedisplacement rail 70 in FIG. 12 and the comparison with the tuft ofbristles 20 according to FIG. 6 and the corresponding working steps, thefollowing should be noted: the tuft of bristles shown in FIG. 6 isintroduced into the bristle tuft channel 75 perpendicularly in relationto the anchor 45. For this tuft of bristles 20, the direction ofmovement I is accordingly likewise perpendicular to the anchor 45. Inthe example now presented, the direction of movement is fixed such thatthe bristle tuft half 35 with the higher bristle ends 37 runs in front.This means that firstly the entire tuft of bristles 20 is introducedinto the bristle tuft channel 75. Subsequently, the edge 77 divides thetuft of bristles 20 along the later transition from the higher bristleends 37 to the lower bristle ends 38. The bristle ends 37 that willlater stand up higher together with the bristle ends 38 that will laterstand up lower on the left side of the tuft 20 are displaced. Afterthat, the lower bristle ends 38 on the right side of the tuft ofbristles 20 are cut to their length. In actual fact this means that thecorresponding segment between the anchor 45 and the higher bristle ends37 is cut away. After that, the tuft of bristles 20 is released againand, in the second step, the working takes place on the left side of thetuft of bristles 20.

In the course of the profiling of the tuft of bristles 20, in additionto the thinning out, it is also possible to profile the higher and lowerbristle ends 37, 38. This either takes place before the thinning outjust described or thereafter; this profiling preferably takes placeafter the thinning out. The higher bristle ends 37 may, for example, becut such that they form a desired profile. For example, an area, forexample of a flat (planar) or undulating form. Other forms are likewiseconceivable. For the finished toothbrush, this may have the end effectin terms of the configuration that, for example, different lengthsbetween the higher and lower bristle ends 37, 38 are achieved within thesame bristle area.

Furthermore, for example, the higher bristle ends 37 may be displacedand the lower bristle ends 38 in the bristle tuft half 36 cut in thisway. However, this step is preferably not carried out and is achieved bya very precise and well-aligned introduction of the bristles 21 into theblind holes 40.

In the process sequence, after the profiling and thinning out of thetufts of bristles 20, the process of rounding the bristles 21 takesplace. When cylindrical bristles 21 are used, all the bristle ends 37,38 are rounded. When bristles that are pointed at one end are used, thehigher bristle ends 37 being pointed, the cylindrical ends, that is tosay the lower bristle ends 38, are rounded. When bristles pointed atboth ends are used, either no profiling and no rounding takes place, ora profiling takes place and only the lower bristle ends 38 are rounded.Accordingly, the tips of the lower bristle ends 38 are also to a certainextent rounded.

In a first step, or in a first sequence of steps, the lower bristle ends38 are thereby rounded. This means that the grinding device that is usedfor the rounding is set to the height of these bristle ends 38, and thehigher bristle ends 37 are preferably not displaced thereby. One or moregrinding wheels arranged one after the other in the process then performthe rounding. Subsequently, in a second step, or in a second sequence ofsteps, the rounding of the higher bristle ends 37 takes place. For thispurpose, the grinding device is set to the height of these bristle ends37. In turn, one or more grinding wheels arranged one after the otherperform the rounding. After that, the functional part of the toothbrushis complete.

One special aspect of the rounding process is that one or more grindingwheels are used for each rounding height. In this case, the same numberor more grinding wheels are used for the second rounding step than forthe first step. This may be necessary because the first rounding couldcause certain damaging effects to the higher bristle ends 37. Therefore,these bristle ends must tend to be rounded longer than the lower bristleends 38 rounded in the first step.

Further possibilities for configuring the rounding process are possibleto minimize any damaging effects on the higher bristle ends 37 duringthe first rounding step. For example, the higher bristle ends 37 couldbe displaced during the first rounding step.

For the realization of toothbrushes according to the invention andtoothbrushes produced according to the invention, a wide variety oftypes of bristle can be used. With preference, cylindrical bristles 22or pointed bristles 23 are used.

FIG. 14a shows the bristle end of a cylindrical bristle 22. Thecylindrical bristles 22 are preferably produced from polyamide (PA).They have a substantially constant nominal diameter Δ_(nom) over thelength of the bristles. The nominal diameter is the diameter at thethickest point of the bristle. The nominal diameter is, for example,0.15 to 0.25 mm. The tip 22 a of the bristle 22 is rounded off in theend state in the toothbrush.

Pointed bristles 23 are presented in FIG. 14b . Pointed bristles 23 arepreferably produced from polyester (PBT) and likewise have a constantdiameter, for example likewise a nominal diameter of 0.15-0.25 mm, overa region of their length. The bristle 23 tapers toward the tip 23 a,beginning at a distance a measured from the tip 23 a. Measured from thetip 23 a, the diameter at the corresponding point corresponds, forexample, to the following values:

% of the nominal diameter Distance (mm) Mean value Tolerance range 0.1 8%  5-15% 1 25% 15-35% 2 45% 30-60% 3 60% 50-80% 4 75% 60-90% 5 80%70-90% 6 85%  >75% 7 90%  >80%

The pointing process is based on reduction of the diameter by means of achemical process. Depending on the length of time during which thebristle is left in the chemical substance, the plastic disintegrates andthe diameter is reduced. The form of the tip can be influenced in thisway.

In principle, two types of pointed bristles 23 exist. Those which have apoint only at one end and those which have a point at both ends of thebristle. As far as the dimensions are concerned, the pointing isdesigned in both cases in the way specified above. The bristles 23 thatare pointed at one end have a point at one end, and at the other end arecylindrically designed and may be rounded off. The bristles 23 pointedat both ends are configured with a point at both ends.

To ensure sufficient stability of the individual filaments, the nominaldiameter is left over a large part of the length at over 75%. The tablegiven above shows that the pointing of the filaments takes placepredominantly over the last 4 to 5 mm. With this configuration, the tip23 a can optimally reach minute fissures and the interdental spaceswhile having sufficient stability of the filament.

To achieve sufficient flexibility of the filaments, a length, fromleaving the blind hole 40 of the head part 10, of between 7 and 13 mm ischosen for all types of bristle.

In the case of toothbrushes according to the invention, the bristles 21may be completely or partially colored. Accordingly, in the case ofpartially colored bristles 21, for example, only the bristle ends oronly one bristle end or else everything with the exception of thebristle ends may be colored. The coloration itself may be designed as anindicator coloration or as a permanent coloration. In the case of theindicator coloration, the color is worn away during the course of use,and thus serves as an indicator of use.

The cylindrical bristles 22, which are produced from polyamide, may forexample be colored with food dyes and be provided with a coating overthe dye. Possible food dyes that can be used by, for example, are forblue “Aluminum Lake of 3,3′-dioxo-2,2′-diindolinyidene-5,5′-disulfonicacid”, for yellow “Aluminum Lake of5-hydroxy-1-(4-sulfophenyl)-4-(4-sulfophenylazo)-3-pyrazolecarboxylicacid” or “Aluminum Lake of 6-hydroxy-5-(4-sulfophenylazo)-2-naphthalenesulfonic acid”. These dyes are designed to be suitable for food contact.

Once the dyes have been applied to bristles 21, the surface is usuallyno longer of such a quality that allows automatic processing ontoothbrush bristle-providing machines. Therefore, the entire bristles,or at least the colored portions of the bristles, are provided with acoating. This coating makes the surface smoother, and so in turn makesautomatic processing possible.

Pointed bristles 23, which are produced from polyester, cannot becolored in this way. The coloration of these bristles 23 must take placeby a chemical process, which however will not be discussed in detail atthis point. The process is known per se.

The advantage of coloration may be that the technical aspect of thebristles of different lengths can be made visible, for example if onlythe higher bristle ends 37 are colored, or if only the lower bristleends 38 are colored. Furthermore, the design as an indicator portion cancreate the benefit for the customer of an indication of use.

With preference, the part of the bristles 21 that comprises the higherbristle ends 37 is colored. The coloration of both ends is likewisepossible.

If it only concerns the tips of the bristles, the coloration has on thefinished toothbrush a length of 2 mm to 10 mm, preferably between 3 mmand 8 mm. On account of the processing, the coloration is longer, oradapted, on the bristles that have not been processed, since otherwisesome parts of the coloration are ground away or cut away. Accordingly,the coloration in the raw material does not have to be of the samelength at both ends of the bristles, just as it can also vary in the endproduct. With preference, the coloration in the end product isnevertheless of the same length at both ends of the bristle if both endsof the bristle are colored.

Furthermore, instead of bristles which have been extruded from a singlematerial, it is possible to use bristles which are co-extruded, i.e.bristles which have been extruded from two or more materials. Thesebristles have an outside diameter of from 0.1 mm to 0.4 mm, preferablyfrom 0.1 mm to 0.25 mm. However, the construction is such that theyconsist of a core and a shell. The core has a diameter of from 0.8 mm to0.16 mm, preferably 0.1 mm to 0.14 mm. The shell around the core has athickness of from 0.02 mm to 0.08 mm, preferably 0.03 mm to 0.05 mm. Thecore and the shell preferably consist of polyester. However, twodifferent materials may also be used. The core and the shell arepreferably not of the same color. It is therefore possible by chemicalor mechanical pointing of the bristles to create the same effect as canbe achieved in the case of bristles with colored tips. The pointinginvolves at least partially removing the shell, and in this way the corebecomes visible from the outside. The rounding of these same bristlesproduces a similar effect, only that in this case the end of thebristles is rounded and not pointed. In this case, the rounding involvesremoving part of the shell and exposing the core to view. The exposingof the core in rounding is much less than in pointing.

In FIGS. 15 to 18, a further configurational variant of the invention isshown. The anchors 45 are introduced into the head part 10 at an angleof 90° or 90°+/−20°, preferably 90°+/−10°, with respect to thelongitudinal axis 29.

In FIGS. 19 to 21, the same is shown on a round head part 10 for anelectric toothbrush with rotating or oscillating motion. In this case,the longitudinal axis 29 of the toothbrush lies substantially at rightangles to the anchors 45 represented.

The tufts of bristles 20 shown in the figures have in turn higherbristle ends 37 and lower bristle ends 38. Preferably, bristles 23 thatare pointed at one end are used. The higher bristle ends 37 are in thiscase formed by pointed ends of the bristles 21, which is graphicallyrepresented in FIGS. 16 to 18 and 20 and 21 by the pointed end of thetufts.

The tufts of bristles 20 may be constructed differently with respect tothe orientation of their higher and lower bristle ends 37, 38. In thiscase it is possible for the tufts of bristles 20 to be uniformlyoriented, as shown for example in FIGS. 16, 18 and 20. This means thatthe bristle tuft halves 35 with the higher bristle ends 37 are alwaysarranged on the same side of the anchor 45, for example always come tolie against the handle of the toothbrush body or are always directedaway from it.

FIG. 17 shows the opposite arrangement of the tufts of bristles 20. Thehigher bristle ends 37 or the relevant bristle tuft halves 35 and alsothe lower bristle ends 38 or the relevant bristle tuft halves 36 of thevarious tufts of bristles 20 are always directed toward one another. Asa result, a better interdental effect is achieved during use of thetoothbrush than in the case of the uniform alignment of the higherbristle ends 37 in the tufts of bristles 20. The clusters penetratebetter into the interdental spaces, because they are surrounded bylarger areas with lower bristle ends 38. This arrangement is alsopossible in the case of brush heads such as those shown in FIGS. 20 and21.

FIG. 21 shows the arrangement in which some of the tufts of bristles 20are oriented to one side and others to the other side. Thisconfigurational variant—arrangement variant—may likewise be realized onelongate head parts 10.

The higher and lower bristle ends 37, 38 are arranged identically withrespect to the anchor 45, as shown in FIG. 2. However, the embodimentsshown in FIGS. 15 to 21 are designed such that preferably no reworkingof the bristles is necessary any longer after the anchors 45 have beenintroduced. There is preferably no reduction in the number of higherbristle ends 37.

Preferably, no rounding of the lower bristle ends 38 takes place either,because bristles 23 that are pointed at one end and are already roundedat the end of the bristle 23 opposite from the pointing before they areintroduced into the brush body are preferably used. The length ratios intufts of bristles 20 with bristles 23 that are pointed at one endcorrespond to those ratios that have been described for the cylindricalbristles 23.

For the production of toothbrushes with tufts of bristles according tothe brush heads in FIGS. 15 to 22, a device such as that shown in FIGS.7 to 11 is used, with the difference that neither the stop 65 nor thematerial channel 60 can or must be adjusted in height during theprocess. In the material channel 60, the bristles 23 that are pointed atone end are arranged such that the rounded end rests on the materialchannel base 61 and the pointed ends point away from the materialchannel base 61. This arrangement achieves a better quality of thealignment of the bristles 23 in the tufts of bristles 20, since thetufts of bristles 20 are in this case not reworked.

If the pointed ends were to lie on the material channel base 61, not allthe bristles 23 would stand up to the same extent, since severalbristles 23 would buckle, since the cross section decreases in theregion 23 a of the pointing. This would have the effect that thealignment would become poorer. In order that different alignments of thehigher and lower bristle ends 37, 38 can nevertheless be achieved duringapplication, the head part 10 is turned in the working process. Thismeans that the bristles 23 are always brought into the same orientationand just the head part is varied in its orientation, and in this way theorientation of the tufts of bristles 20 in the finished toothbrush doesnot have to be uniform.

In FIG. 22, a head part 10 for an electric toothbrush with rotating oroscillating motion is shown. The anchors 45 are in this case arranged atan angle of 90° or 90°+/−20°, preferably 90°+/−10°, with most preference90°, in relation to the radius of the head part 10. They lie at atangent to the circles formed by the center points of the tufts ofbristles 20.

The tufts of bristles 20 shown in the figures have in turn higherbristle ends 37 and lower bristle ends 38. Bristles 23 that are pointedat one end are preferably used. The higher bristle ends 37 are in thiscase formed by pointed ends of the bristles 23.

In this arrangement of the anchors 45, all the tufts of bristles 20 maybe oriented identically, for example such that the higher bristle ends37 of each tuft of bristles 20 are directed toward the center point ofthe bristle area or else such that they are directed away from it.

Furthermore, the tufts of bristles 20 may also have a uniformorientation of the higher and lower bristle ends 37, 38 in the manner ofa circle, for example in the configuration that the higher and lowerbristle ends 37, 38 of different tufts of bristles 20 are respectivelyoriented toward one another. Furthermore, it is also possible for thetufts of bristles 20 to be oriented alternately on the circles.

A further configurational variant of the tangential arrangement of theanchors 45 is that, in the bristle area with a round or elongatedextent, not all the tufts of bristles 20 have anchors 45 in thealignment mentioned. This is for example so that certain anchors 45 arenevertheless oriented at right angles to the longitudinal axis 29, orhave a different orientation.

It is also possible to design a bristle area in which some of thebristle holes are created in a circular arrangement, but others areconfigured in rows parallel to the longitudinal direction. Here onceagain, the anchor alignment is not uniform over the entire bristle area.

A sequence explaining how the production of bristles 23 that are pointedat one end and have a rounded-off opposite end and coloration of thepointing takes place is described in conjunction with FIG. 23.

The bristle filaments are introduced into the process on the bristlestrand. In this case, a multiplicity of filaments are bundled by meansof a sheath and have a length which is a multiple of the final length ofthe bristles in the toothbrush. The length may, for example, lie in therange from 80 cm to 120 cm. On the one hand the sheath serves here forthe bundling of the filaments, in order that they remain lying againstone another, and on the other hand the sheath has a protective function,that the filaments are soiled or damaged less.

In a first step, these strands with bristle filaments are prepared forthe working operation. This may, for example, comprise at leastpartially stripping back the sheath and clamping them in the device in away corresponding to the subsequent working.

The working step comprises, for example, the rounding of the free end ofthe bristle strand. In this case, all the bristle ends of the bristlestrand of are rounded with one another. The grinding element, forexample a diamond grinder, rounds all the bristle ends of the bristlestrands in one step.

Since the bristle strand has been at least partially freed of the sheathin the previous step, the bristle filaments can move out of line duringthe rounding process. An individual movement of the filaments is allowedto a limited extent. The rounding is better and more regular as aresult.

After that, the bristle strand is sheathed again, i.e. provided with asheath, and is subsequently cut to the size of a delivery bundle ofbristles. These two steps may also happen in the reverse sequence. Thedelivery bundle of bristles is in this case a piece of the bristlestrand of a length that corresponds approximately to more than doublethe bristle length.

Once the bristles have then been rounded at one end, the working of theother end of the bristles follows. This end is pointed and, if need, becolored. The pointing takes place in a first step and is performed bychemical means; the chemicals undertake the removal of material. Afterthat, the pointed ends are colored; possible parameters and propertiesof the coloration have already been mentioned above, and provided with acoating. The coating serves the purpose of making the nature of thesurface (frictional values, etc.) of the individual bristles such thatthey can be processed by machine.

Subsequently, the bristles that are pointed at one end are packed indelivery bundles of bristles (which then have a different appearancethan the delivery bundles of bristles before). In this case, the tips ofall the bristles point in the same direction and the delivery bundles ofbristles have a diameter of, for example, 3 to 5 cm. The form of thedelivery bundles of bristles is preferably of an elliptical torectangular configuration, on account of their transporting medium, forexample an elongate cardboard packaging.

The length of the delivery bundles of bristles is from 40 mm to 60 mm,preferably from 45 mm to 55 mm, with a width of from 25 mm to 40 mm,preferably from 30 mm to 35 mm. In this configuration/delivery form, thewidth of the delivery bundle of bristles corresponds substantially tothe width of the material channel 60, cf. FIG. 7. This allows easierintroduction of the delivery bundles of bristles into the materialchannel 60, without the fragile delivery bundles of bristles having tobe deformed too much. Furthermore, in this form, the delivery bundles ofbristles can be transported in an easier and more space-saving manner inan elongate cardboard packaging. Furthermore, the delivery bundles ofbristles have laterally around the bundle a retaining strip of limitedlength, which holds the large number of pointed bristles together. Onaccount of the limited length of the retaining strip, virtually nopressure is exerted on the pointed bristles in the delivery bundle ofbristles.

For the production of toothbrushes according to the invention, variousplastics may be used. Possibilities from the area of thermoplastics are,by way of example:

-   -   styrene polymers such as styrene acrylonitrile (SEN),        polystyrene (PS), acrylonitrile butadiene styrene (ABS), styrene        methyl methacrylates (SMMA), styrene butadiene (SB, for example        BDS K-Resin from the Chevron Phillips Chemical Company);    -   polyolefins such as polypropylene (PP), polyethylene (PE), for        example also in the forms of high-density polyethylene (HDPE) or        low-density polyethylene (LDPE);    -   polyesters such as polyethylene terephthalate (PET) in the form        of acid-modified polyethylene terephthalate (PETA) or        glycol-modified polyethylene terephthalate (PETG), such as GN005        or 6763 from the Eastman Chemical Company, polybutylene        terephthalate (PBT), acid-modified poly(cyclohexanedimethanol        terephthalate) (PCT-A), such as BR003 from the Eastman Chemical        Company, glycol-modified poly(cyclohexanedimethanol        terephthalate) (PCT-G), such as DN004 from the Eastman Chemical        Company;    -   cellulose derivatives such as cellulose acetate (CA), cellulose        acetobutyrate (CAB), cellulose propionate (CP), cellulose        acetate phthalate (CAP), cellulose butyrate (CB);    -   polyamides (PA), such as PA 6.6, PA 6.10, PA 6.12;    -   polymethylmethacrylate (PMMA);    -   polycarbonate (PC);    -   polyoxymethylene (POM);    -   polyvinyl chloride (PVC); and    -   polyurethane (PUR).

Examples from the area of thermoplastic elastomers (TPEs) are:

-   -   thermoplastic polyurethane elastomers (TPE-U);    -   thermoplastic styrene elastomers (TPE-S), such as for example a        styrene-ethylene-butylene-styrene copolymer (SEBS) or        styrene-butadiene-styrene copolymer (SBS);    -   thermoplastic polyamide elastomers (TPE-A), such as for example        Grilflex® from EMS Chemie AG;    -   thermoplastic polyolefin elastomers (TPE-O); and    -   thermoplastic polyester elastomers (TPE-E).

In the case of a non-transparent brush, PP is used with preference asthe hard component, with most preference PP with a modulus of elasticityof 1000-2400 N/mm2, preferably 1300 to 1800 N/mm2. For a brush of atransparent design, polyesters are used with preference as the hardcomponent, such as the cited BR003, CAP, PA, PMMA, SAN or ABS.

A TPE-S is used with preference as the soft component. The Shore Ahardnesses of the soft plastic preferably lie below 90 Shore A. The softcomponent may be integrated both as a component on the handle body ofthe toothbrush and as a massaging or cleaning element in the toothbrushhead 10.

The construction of the bristle area is in principle possible with greatvariability. Cylindrical bristles 21, 22, 23 that are pointed at one endand at both ends may be combined in any desired way in the bristle area.The tufts of bristles 20 may be directly integrated and combined in anydesired number as tufts of bristles 20 with higher and lower bristleends; also possible, in addition, are the conventional forms of tufts ofbristles, in which all the bristles in the tuft stand up to the sameheight. Furthermore, soft-elastic massaging and/or cleaning elements maybe combined in the head part 10 in any desired arrangement with theaforementioned types of bristle and types of tuft.

The tufts of bristles 20 with higher and lower bristle ends 37, 38 may,for example, be arranged alternating with conventional tufts of bristlesin the form of transverse rows, it being possible for the conventionaltufts of bristles to have their bristle ends lying lower than the higherbristle ends 38. The tufts of bristles 20 with higher and lower bristleends 37, 38 may form closed contours around other tufts of bristles orelse around soft-elastic massaging and/or cleaning elements. Forexample, they may be arranged such that they surround the bristle area.

One special configurational variant of tufts of bristles 20 with higherand lower bristle ends 37, 38 is the arrangement of these tufts ofbristles 20 at an angle deviating from 90° with respect to the head part10. This means that slanting tufts of bristles 20 are formed, which mayalso cross and in this way make X-shaped arrangements possible. Theseare possible longitudinally and transversely on the brush head. Forexample, a toothbrush head 10 may be designed as having on it transverserows in which all the tufts of bristles 20 are inclined in the samedirection. The thinning out/profiling is in this case possible in thesame manner as for the straight tufts of bristles. The difference is inthe appearance of the tufts of bristles. In the present case, the planeof the higher bristle ends 37 and the plane of the lower bristle ends 38are no longer perpendicular to the axis of the blind hole 40 in whichthey have been introduced or in relation to the longitudinal axis of thebristles 21. The planes are in this case parallel to the head area ofthe toothbrush.

A further configurational possibility is the variable arrangement of theanchors 45. If the toothbrush or the head part 10 is turnedcorrespondingly during the bristle-providing process, the anchors 45 arefixed at different angles in relation to one another in the brush head.The asymmetric punching of the tufts of bristles 20, that is to say thevariable arrangement of higher and lower bristle ends 37, 38, is madepossible as a result.

A certain discipline is nevertheless necessary, in order that thinningout—as described further above—can take place; this means that the tuftsof bristles 20 must be arranged in certain transverse rows. The variablearrangement of the anchors 45, and accordingly of the higher bristleends 37, makes the thinning out less regular, when considered over theentire bristle area, or the various tufts of bristles are thinned out todifferent degrees.

The alternative to this, that the anchor positions, and consequently theorientation of the tufts of bristles 20, are varied in the bristle area,is that all the tufts of bristles 20 are oriented identically and nomirror-inversion of the higher bristle ends 37 with respect to thelongitudinal axis 29 is obtained.

All the parts of the toothbrush body, that is to say the handle part,the neck part 15 and the head part 10, may be produced from one or morehard components and additionally with one or more soft components. Thesoft component is optional however.

The production process according to the invention and the toothbrushhead according to the invention are not only suitable for handheldtoothbrushes but also for vibrating/acoustic toothbrushes or electrictoothbrushes with rotating, oscillating, swiveling head parts 10 or withhead parts 10 which perform a back and forth movement in thelongitudinal direction, or combinations thereof.

It goes without saying that the configurational variants shown anddescribed are given by way of example and the individual refinements andelements of these configurational variants may be combined with otherconfigurational variants without departing from the scope of thisinvention.

In the case of all the embodiments shown, the tufts of bristles 20 formtwo bristle tuft halves 35, 36 by the U-shaped bending or folding aroundthe relevant anchor 45. The bristle tuft half 36 has in each case—as aresult of the asymmetric folding—only bristles 21 with lower bristleends 38. The other bristle tuft half 35 has in each case bristles 21 ofwhich the bristle ends 37 stand up higher with respect to the bristleends 38 of the bristle tuft half 36. In this case, all the bristle ends37 of the bristle tuft half 35 may stand up higher, as is preferably thecase with the embodiments according to FIGS. 15 to 22. However, inaddition to the bristles 21 with higher bristle ends 37, the bristletuft halves 35 may also have ones with lower bristle ends 38, as isshown as a preference in the case of the exemplary embodiments accordingto FIGS. 1 to 6.

The present invention also concerns a toothbrush with a handle and abristle-carrying head part 10, which are connected to each other by aneck part 15, the head part 10 having a multiplicity of tufts ofbristles 20 consisting of bristles 21, respectively forming two bristletuft halves 35, 36 and fastened in the head part 10 by means of ananchor 45. The tufts of bristles 20 are arranged along lines that arepreferably continuous. The lines extend at a distance from one anotherthat is preferable constant. The lines are preferably concentriccircular lines. The anchors 45 of the tufts of bristles 20 run at leastapproximately, preferably exactly, tangentially in relation to thelines. The one bristle tuft half 35 has bristle ends 37 standing uphigher in relation to the bristle ends 38 of the other bristle tuft half36.

It is preferred in this respect for all the tufts of bristles 20 thatare assigned to a line to be aligned identically; the outer bristle tufthalf 35, 36 with respect to the line is in each case the one with thelower bristle ends 38 or the one with the higher bristle ends 37.

It is also preferred in this respect for the tufts of bristles 20 thatare assigned to all the lines to be aligned identically; the outerbristle tuft halves 35, 36 with respect to the lines are the ones withthe lower bristle ends 38 or the ones with the higher bristle ends 37.

It is also preferred in this respect for the tufts of bristles 20 thatare respectively assigned to a line to be aligned identically; the outerbristle tuft half 35 or 36 with respect to the relevant line is in eachcase the one with the lower bristle ends 38 or the one with the higherbristle ends 37. The tufts of bristles 20 assigned to the neighboringline are arranged the other way round in relation to one another. Thebristle tuft halves 35 and 36 of the tufts of bristles 20 following oneanother in the radial direction are consequently facing one another.

1. A toothbrush with a handle and a bristle-carrying head part, whichare connected to each other by a neck part, the head part having amultiplicity of tufts of bristles comprising bristles that are pointedat both bristle ends, respectively forming two bristle tuft halves andbeing fastened in the head part by means of an anchor, wherein thebristles are folded asymmetrically about the anchor and one bristle tufthalf has bristle ends standing up higher in relation to the bristle endsof the other bristle tuft half by 0.5 mm to 5 mm.
 2. The toothbrush asclaimed in claim 1, wherein the one bristle tuft half has bristle endsstanding up higher in relation to the bristle ends of the other bristletuft half by 2 mm to 3 mm.
 3. The toothbrush as claimed in claim 1,wherein the bristles have a nominal diameter at the thickest point ofthe bristle of 0.15 mm to 0.25 mm.
 4. The toothbrush as claimed in claim1, wherein a diameter of the bristles measured at a distance of 0.1 mmfrom a tip of the pointed bristles corresponds to a value of 5% to 15%of the nominal diameter of the bristles.
 5. The toothbrush as claimed inclaim 1, wherein a diameter of the bristles measured at a distance of 1mm from a tip of the pointed bristles corresponds to a value of 15% to35% of the nominal diameter of the bristles.
 6. The toothbrush asclaimed in claim 4, wherein the diameter of the bristles measured at adistance of 0.1 mm from the other tip of the pointed bristlescorresponds to a value of 5% to 15% of the nominal diameter of thebristles.
 7. The toothbrush as claimed in claim 5, wherein the diameterof the bristles measured at a distance of 1 mm from the other tip of thepointed bristles corresponds to a value of 15% to 35% of the nominaldiameter of the bristles.
 8. The toothbrush as claimed in claim 1,wherein the pointed ends of the bristles are formed by at least one of achemical or a mechanical pointing process.
 9. The toothbrush as claimedin claim 1, wherein the bristles of the multiplicity of tufts ofbristles have a cylindrical cross section.
 10. The toothbrush as claimedin claim 1, wherein the bristles have a constant diameter of 0.15 mm to0.25 mm over a region of their length.
 11. A method of producing thetoothbrush according to claim 1 with a handle and a head part which areconnected to each other by a neck part, the head part having amultiplicity of tufts of bristles comprising bristles that are pointedat both bristle ends, the method comprising: folding the bristlesasymmetrically about an anchor, whereby one bristle tuft half hasbristle ends standing up higher in relation to the bristle ends of theother bristle tuft half by 0.5 mm to 5 mm; and fastening the tufts ofbristles in blind holes in the head part by means of the anchor.
 12. Themethod as claimed in claim 11, wherein one bristle tuft half has bristleends standing up higher in relation to the bristle ends of the otherbristle tuft half by 2 mm to 3 mm.
 13. The method as claimed in claim11, wherein the bristles have a nominal diameter at a thickest point ofthe bristle of 0.15 mm to 0.25 mm.
 14. The method as claimed in claim11, wherein a diameter of the bristles measured at a distance of 0.1 mmfrom a tip of the pointed bristles corresponds to a value of 5% to 15%of the nominal diameter of the bristles.
 15. The method as claimed inclaim 11, wherein a diameter of the bristles measured at a distance of 1mm from a tip of the pointed bristles corresponds to a value of 15% to35% of the nominal diameter of the bristles.
 16. The method as claimedin claim 14, wherein the diameter of the bristles measured at a distanceof 0.1 mm from the other tip of the pointed bristles corresponds to avalue of 5% to 15% of the nominal diameter of the bristles.
 17. Themethod as claimed in claim 15, wherein the diameter of the bristlesmeasured at a distance of 1 mm from the other tip of the pointedbristles corresponds to a value of 15% to 35% of the nominal diameter ofthe bristles.
 18. The method as claimed in claim 11, wherein the methodincludes forming the pointed ends of the bristles by at least one of achemical or a mechanical pointing process.
 19. The method as claimed inclaim 11, wherein the bristles have a constant diameter of 0.15 mm to0.25 mm over a region of their length.